Heretofore tooth brush devices have been provided for dispensing dental floss, such as the tooth brushes shown in U.S. Pat. Nos. 2,113,439 and 3,782,397. However, in such devices, in which the dental floss is retained on a spool within an enclosed chamber, the spool of floss is not visible and may be exhausted without warning to the user. To avoid this, it would be desirable for the user to know the remaining supply of dental floss, so that if the tooth brush device is disposable, another tooth brush device can be made available for use prior to exhaustion of floss. In the case where the tooth brush device is provided with a replaceable spool of dental floss, it is also desirable to monitor the usage of dental floss so that a new spool may be available when required for replacement.